// run command "tsc greater.ts" 会编译生成 js文件

class Student {
    fullName: string;
    constructor(public firstname, public middleInitial, public lastName) {
        this.fullName = firstname +  " " + middleInitial + "  " + lastName;
    }
}

interface Person {
    firstName: string;
    lastName: string;
}

function greeter(person: Person) {
    return "Hello, " + person.firstName + " " + person.lastName;
}

// let user = "Jane User";
// let user = [1,2,3];
let user: Person = {
    firstName: '',
    lastName: '',
}
// let user = new Student("Jane", "M.", "User");


document.body.innerHTML = greeter(user);